Soybean cultivar 3539836

ABSTRACT

A novel soybean cultivar, designated 3539836, is disclosed. The invention relates to the seeds of soybean cultivar 3539836, to the plants of soybean 3539836 and to methods for producing a soybean plant produced by crossing the cultivar 3539836 with itself or another soybean variety. The invention further relates to hybrid soybean seeds and plants produced by crossing the cultivar 3539836 with another soybean cultivar.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinctive soybean cultivar,designated 3539836. There are numerous steps in the development of anynovel, desirable plant germplasm. Plant breeding begins with theanalysis and definition of problems and weaknesses of the currentgermplasm, the establishment of program goals, and the definition ofspecific breeding objectives. The next step is selection of germplasmthat possess the traits to meet the program goals. The goal is tocombine in a single variety an improved combination of desirable traitsfrom the parental germplasm. These important traits may include higherseed yield, resistance to diseases and insects, better stems and roots,tolerance to drought and heat, and better agronomic quality.

Choice of breeding or selection methods depends on the mode of plantreproduction, the heritability of the trait(s) being improved, and thetype of cultivar used commercially (e.g., F₁ hybrid cultivar, purelinecultivar, etc.). For highly heritable traits, a choice of superiorindividual plants evaluated at a single location will be effective,whereas for traits with low heritability, selection should be based onmean values obtained from replicated evaluations of families of relatedplants. Popular selection methods commonly include pedigree selection,modified pedigree selection, mass selection, and recurrent selection.

The complexity of inheritance influences choice of the breeding method.Backcross breeding is used to transfer one or a few favorable genes fora highly heritable trait into a desirable cultivar. This approach hasbeen used extensively for breeding disease-resistant cultivars. Variousrecurrent selection techniques are used to improve quantitativelyinherited traits controlled by numerous genes. The use of recurrentselection in self-pollinating crops depends on the ease of pollination,the frequency of successful hybrids from each pollination, and thenumber of hybrid offspring from each successful cross.

Each breeding program should include a periodic, objective evaluation ofthe efficiency of the breeding procedure. Evaluation criteria varydepending on the goal and objectives, but should include gain fromselection per year based on comparisons to an appropriate standard,overall value of the advanced breeding lines, and number of successfulcultivars produced per unit of input (e.g., per year, per dollarexpended, etc.).

Promising advanced breeding lines are thoroughly tested and compared toappropriate standards in environments representative of the commercialtarget area(s) for three or more years. The best lines are candidatesfor new commercial cultivars; those still deficient in a few traits maybe used as parents to produce new populations for further selection.

These processes, which lead to the final step of marketing anddistribution, usually take from eight to 12 years from the time thefirst cross is made. Therefore, development of new cultivars is atime-consuming process that requires precise forward planning, efficientuse of resources, and a minimum of changes in direction.

A most difficult task is the identification of individuals that aregenetically superior, because for most traits the true genotypic valueis masked by other confounding plant traits or environmental factors.One method of identifying a superior plant is to observe its performancerelative to other experimental plants and to a widely grown standardcultivar. If a single observation is inconclusive, replicatedobservations provide a better estimate of its genetic worth.

The goal of plant breeding is to develop new, unique and superiorsoybean cultivars. The breeder initially selects and crosses two or moreparental lines, followed by repeated selfing and selection, producingmany new genetic combinations. The breeder can theoretically generatebillions of different genetic combinations via crossing, selfing andmutations. The breeder has no direct control at the cellular level.Therefore, two breeders will never develop the same line, or even verysimilar lines, having the same soybean traits.

Each year, the plant breeder selects the germplasm to advance to thenext generation. This germplasm is grown under unique and differentgeographical, climatic and soil conditions, and further selections arethen made, during and at the end of the growing season. The cultivarswhich are developed are unpredictable. This unpredictability is becausethe breeder's selection occurs in unique environments, with no controlat the DNA level (using conventional breeding procedures), and withmillions of different possible genetic combinations being generated. Abreeder of ordinary skill in the art cannot predict the final resultinglines he develops, except possibly in a very gross and general fashion.The same breeder cannot produce the same cultivar twice by using theexact same original parents and the same selection techniques. Thisunpredictability results in the expenditure of large research monies todevelop a superior new soybean cultivar.

Pedigree breeding and recurrent selection breeding methods are used todevelop cultivars from breeding populations. Breeding programs combinedesirable traits from two or more cultivars or various broad-basedsources into breeding pools from which cultivars are developed byselfing and selection of desired phenotypes. The new cultivars areevaluated to determine which have commercial potential.

Pedigree breeding is used commonly for the improvement ofself-pollinating crops. Two parents which possess favorable,complementary traits are crossed to produce an F₁. An F₂ population isproduced by selfing one or several F₁ 's or by intercrossing two F₁ 's(sib mating). Selection of the best individuals may begin in the F₂population; then, beginning in the F₃, the best individuals in the bestfamilies are selected. Replicated testing of families can begin in theF₄ generation to improve the effectiveness of selection for traits withlow heritability. At an advanced stage of inbreeding (i.e., F₆ and F₇),the best lines or mixtures of phenotypically similar lines are testedfor potential release as new cultivars.

Mass and recurrent selections can be used to improve populations ofeither self- or cross-pollinating crops. A genetically variablepopulation of heterozygous individuals is either identified or createdby intercrossing several different parents. The best plants are selectedbased on individual superiority, outstanding progeny, or excellentcombining ability. The selected plants are intercrossed to produce a newpopulation in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror inbred line which is the recurrent parent. The source of the trait tobe transferred is called the donor parent. The resulting plant isexpected to have the attributes of the recurrent parent (e.g., cultivar)and the desirable trait transferred from the donor parent. After theinitial cross, individuals possessing the phenotype of the donor parentare selected and repeatedly crossed (backcrossed) to the recurrentparent. The resulting plant is expected to have the attributes of therecurrent parent (e.g., cultivar) and the desirable trait transferredfrom the donor parent.

The single-seed descent procedure in the strict sense refers to plantinga segregating population, harvesting a sample of one seed per plant, andusing the one-seed sample to plant the next generation. When thepopulation has been advanced from the F₂ to the desired level ofinbreeding, the plants from which lines are derived will each trace todifferent F₂ individuals. The number of plants in a population declineseach generation due to failure of some seeds to germinate or some plantsto produce at least one seed. As a result, not all of the F₂ plantsoriginally sampled in the population will be represented by a progenywhen generation advance is completed.

In a multiple-seed procedure, soybean breeders commonly harvest one ormore pods from each plant in a population and thresh them together toform a bulk. Part of the bulk is used to plant the next generation andpart is put in reserve. The procedure has been referred to as modifiedsingle-seed descent or the pod-bulk technique.

The multiple-seed procedure has been used to save labor at harvest. Itis considerably faster to thresh pods with a machine than to remove oneseed from each by hand for the single-seed procedure. The multiple-seedprocedure also makes it possible to plant the same number of seeds of apopulation each generation of inbreeding. Enough seeds are harvested tomake up for those plants that did not germinate or produce seed.

Descriptions of other breeding methods that are commonly used fordifferent traits and crops can be found in one of several referencebooks (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr,1987).

Proper testing should detect any major faults and establish the level ofsuperiority or improvement over current cultivars. In addition toshowing superior performance, there must be a demand for a new cultivarthat is compatible with industry standards or which creates a newmarket. The introduction of a new cultivar will incur additional coststo the seed producer, the grower, processor and consumer; for specialadvertising and marketing, altered seed and commercial productionpractices, and new product utilization. The testing preceding release ofa new cultivar should take into consideration research and developmentcosts as well as technical superiority of the final cultivar. Forseed-propagated cultivars, it must be feasible to produce seed easilyand economically.

Soybean, Glycine max (L), is an important and valuable field crop. Thus,a continuing goal of plant breeders is to develop stable, high yieldingsoybean cultivars that are agronomically sound. The reasons for thisgoal are obviously to maximize the amount of grain produced on the landused and to supply food for both animals and humans. To accomplish thisgoal, the soybean breeder must select and develop soybean plants thathave the traits that result in superior cultivars.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel soybean cultivar,designated 3539836. This invention thus relates to the seeds of soybeancultivar 3539836, to the plants of soybean 3539836 and to methods forproducing a soybean plant produced by crossing the soybean 3539836 withitself or another soybean line.

DEFINITIONS

In the description and tables which follow, a number of terms are used.In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided:

Maturity. Plants are considered mature when 95% of the pods have reachedtheir mature color.

Seed Yield (Bushels/Acre). The yield in bushels/acre is the actual yieldof the grain at harvest.

Lodging Resistance. Lodging is rated on a scale of 1 to 9. A score of 9indicates erect plants. A score of 5 indicates plants are leaning at a450 angle in relation to the ground and a score of 1 indicates plantsare laying on the ground.

Phytophthora Tolerance. Tolerance to Phytophthora root rot is rated on ascale of 1 to 9, with a score of 9 being the best or highest toleranceranging down to a score of 1 which indicates the plants have notolerance to phytophthora.

Emergence. This score indicates the ability of the seed to emerge whenplanted 3- deep in sand and with a controlled temperature of 25° C. Thenumber of plants that emerge each day are counted. Based on this data,each genotype is given a 1 to 9 score based on its rate of emergence andpercent of emergence. A score of 9 indicates an excellent rate andpercent of emergence, an intermediate score of 5 indicates averageratings and a 1 score indicates a very poor rate and percent ofemergence.

Iron-Deficiency Chlorosis. Plants are scored I to 9 based on visualobservations. A score of 1 indicates the plants are dead or dying causedby iron-deficiency chlorosis, a score of 5 means plants haveintermediate health with some leaf yellowing and a score of 9 means nostunting of the plants or yellowing of the leaves.

Brown Stem Rot. This is a visual disease score from I to 9 comparing allgenotypes in a given test. The score is based on leaf symptoms ofyellowing and necrosis caused by brown stem rot. A score of 9 indicatesno symptoms. Visual scores range down to a score of 1 which indicatessevere symptoms of leaf yellowing and necrosis.

Shattering. The amount of pod dehiscence prior to harvest. Poddehiscence involves seeds falling from the pods to the soil. This is avisual score from 1 to 9 comparing all genotypes within a given test. Ascore of 9 means pods have not opened and no seeds have fallen out. Ascore of 5 indicates approximately 50% of the pods have opened, withseeds falling to the ground and a score of 1 indicates 100% of the podsare opened.

Plant Height. Plant height is taken from the top of soil to top of theplant and is measured in inches.

DETAILED DESCRIPTION OF THE INVENTION

Soybean cultivar 3539836 has superior characteristics and was developedfrom the cross 851008-021×895325. F₃ seed was advanced by the singleseed decent method of breeding. In the fall of 1991, F₃ derived singleplants were selected and harvested individually. These lines were testedin experimental plots in 1992 at Adel, Iowa. The highest yielding lineswere retained for additional testing in 1993. A second year of testingwas conducted during 1993 at four midwest locations where the lines wereadapted. 35398 was advanced to the 1994 Elite trials at twelvelocations. In the fall of 1994, 50 F₆ derived single plants of 35398were selected and harvested individually.

During 1995, these 50 plant rows were evaluated for maturity and othervisual characteristics. Also during 1995, 35398 was evaluated atthirteen midwest locations. 35398 was advanced to the 1996 Elite Trialwhere it was evaluated at thirteen midwest locations. 24 plant rowselections were advanced to the 1996 Plant Row Yield Trials.

Based on 1994-1996 Elite data on 35398 and Plant Row Yield Trial datafrom 6 Midwest locations, selection 3539836 was advanced to the 1997Elite Trial.

Table 1 shows 1997 Elite Trial data from 13 locations.

Some of the criteria used to select in various generations include: seedyield, lodging resistance, emergence, disease tolerance, maturity, lateseason plant intactness, plant height and shattering resistance.

The cultivar has shown uniformity and stability for the traits, asdescribed in the following variety description information. It has beenself-pollinated a sufficient number of generations with carefulattention to uniformity of plant type. The line has been increased withcontinued observation for uniformity.

Soybean cultivar 3539836 has the following morphologic and othercharacteristics (based primarily on data collected at Adel, Iowa):

VARIETY DESCRIPTION INFORMATION

1. Seed Shape: Spherical Flattened (L/W ratio >1.2; LIT ratio =<1.2)

2. Seed Coat Color: (Mature Seed)--Yellow

3. Seed Coat Luster: (Mature Hand Shelled Seed)--Dull

4. Hilum Color: (Mature Seed)--Brown

5. Cotyledon Color: (Mature Seed)--Yellow

6. Leaflet Shape: Ovate

7. Leaflet Size: Medium

8. Leaf Color: Dark Green

9. Flower Color: Purple

10. Pod Color: Brown

11. Plant Pubescence Color: Light Tawny

12. Plant Types: Intermediate

13. Plant Habit: Indeterminate

14. Maturity Group: Ill

15. Relative Maturity: 3.5

16. Plant Lodging Score: 6.3

17. Plant Height: 79 cm.

18. Seed Content--% Protein: 35.2

% Oil: 19.8

19. Seed Size G/100 Seeds: 18.6

This invention is also directed to methods for producing a soybean plantby crossing a first parent soybean plant with a second parent soybeanplant, wherein the first or second soybean plant is the soybean plantfrom the line 3539836. Further, both first and second parent soybeanplants may be from the cultivar 3539836. Therefore, any methods usingthe cultivar 3539836 are part of this invention: selfing, backcrosses,hybrid breeding, and crosses to populations. Any plants produced usingcultivar 3539836 as a parent are within the scope of this invention.

As used herein, the term "plant" includes plant cells, plantprotoplasts, plant cells of tissue culture from which soybean plants canbe regenerated, plant calli, plant clumps, and plant cells that areintact in plants or parts of plants, such as pollen, flowers, seeds,pods, leaves, stems, and the like. Thus, another aspect of thisinvention is to provide for cells which upon growth and differentiationproduce the cultivar 3539836.

The cultivar 3539836 is similar to Stine 3660 with numerous differences.For example, 3539836 has brown hila while Stine 3660 has black hila.Additionally, 3539836 has purple flowers while Stine 3660 has whiteflowers.

As shown in Table 1, soybean cultivar 3539836 yields higher thanBR65950RR, Stine 3264, CM3773RR, Stine 3643 and Stine 3660 with theincrease over all comparisons being significant at the 0.01 level ofprobability.

TABLES

In the table that follows, the traits and characteristics of soybeancultivar 3539836 are compared to elite commercial soybeans of similarmaturity. In Table 1 the year of the test is shown in the second columnand the number of locations is in the third column and the number ofobservations is in the fourth column. Column 5 indicates the genotypeand column 6 shows the mean yield in bushels per acre. Column 7 presentsthe t value and columns 8 and 9 present the critical t values at the.05% and .01% levels of significants, respectfully. Cultivar 3539836 hassuperior yielding ability over all tested elite soybeans with a similarmaturity rating.

                                      TABLE 1    __________________________________________________________________________    PAIRED COMPARISONS            # of               # of      Mean    Critical                                     Critical    Comp #        Year            Loc.               Obs.                   Genotype                         Yield                             t Value                                 t @ .05                                     t @ .01    __________________________________________________________________________    1   1997            13 38  3539836                         51.9                             3.84**                                 1.69                                     2.43                   BR65950RR                         47.5    2   1997            13 38  3539836                         51.9                             6.58**                                 1.69                                     2.43                   Stine 3264                         44.9    3   1997            13 38  3539836                         51.9                             6.15**                                 1.69                                     2.43                   CM3773RR                         45.1    4   1997            13 38  3539836                         51.9                             3.02**                                 1.69                                     2.43                   Stine 3643                         49.1    5   1997            13 38  3539836                         51.9                             3.32**                                 1.69                                     2.43                   Stine 3660                         47.9    __________________________________________________________________________     *Significant at .05 level of probability     **Significant at .01 level of probability

A deposit of the Stine Seed Farm, Inc. proprietary soybean cultivar3539836 disclosed above and recited in the appended claims has been madewith the American Type Culture Collection (ATCC), 10801 UniversityBoulevard, Manassas, Va. 20110. The date of deposit was Oct. 8, 1998.The deposit of 2,500 seeds were taken from the same deposit maintainedby Stine Seed Farm, Inc. since prior to the filing date of thisapplication. All restrictions upon the deposit have been removed, andthe deposit is intended to meet all of the requirements of 37 C.F.R.§1.801-1.809. The ATCC accession number is ATCC 203342. The deposit willbe maintained in the depository for a period of 30 years, or 5 yearsafter the last request, or for the effective life of the patent,whichever is longer, and will be replaced as necessary during thatperiod.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity andunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the invention, as limited only bythe scope of the appended claims.

What is claimed is:
 1. A soybean seed designated 3539836 and having ATCCAccession No.
 203342. 2. A plant or its parts produced by growing theseed of claim
 1. 3. Pollen of the plant of claim
 2. 4. An ovule of theplant of claim
 2. 5. A soybean plant having all of the physiological andmorphological characteristics of the soybean plant of claim
 2. 6. Tissueculture of the plant of claim
 2. 7. A soybean plant regenerated from thetissue culture of claim 6 wherein the regenerated soybean plant has allof the physiological and morphological characteristics of a plant grownfrom a soybean seed designated
 3539836. 8. A method for producing ahybrid soybean seed comprising crossing a first parent soybean plantwith a second parent soybean plant and harvesting the resultant hybridsoybean seed, wherein said first or second parent soybean plant is thesoybean plant of claim
 2. 9. A hybrid seed produced by the method ofclaim
 8. 10. A hybrid plant or its parts produced by growing said hybridsoybean seed of claim
 9. 11. Seed produced from said hybrid plant ofclaim 10.